Englishfor English speakers
in
Preposition
—
Used to show that something is inside something else.
The cat is in the box.
—
Used to show that someone is at home, or is available.
Is John in?
The Doctor is now in.
—
Used to show movement towards the inside.
The rain came in through the window.
Zucker
noun
—
A kind of rat bred as a genetic model for research on obesity and hypertension.